title: Ubiquitin ligase A20 regulates p53 protein in human colon epithelial cells.
abstract: BACKGROUND
  Intestinal polyps may further develop into colon cancer; the pathogenesis is not clear. The p53 gene is an important anti-cancer gene in the body, which is suppressed in cancer. The ubiquitin E3 ligase A20 (A20) plays a role in regulating the activities of epithelial cells. This study was designed to investigate the role of the colon polyp epithelium-derived A20 in the pathogenesis of colon cancer.
  
  
  RESULTS
  Eighty-eight colon cancer patients and 136 colon polyp patients were recruited into this study. Human colon cancer tissue, the epithelium of adenomas polyp and hyperplastic polyp showed high levels of A20, which had a positive correlation with the cancerous tendency of colon polyps. The levels of A20 were much higher in the adenomas and hyperplastic polyps than that in the inflammatory polyps; the latter showed less cancerous tendency. A20 bound p53 to form complexes in colon cancer tissue and colon polyps. Over expression of A20 suppresses P53 protein levels in the HEK293 cells.
  
  
  CONCLUSIONS
  A20 may play an important role in the cancerous tendency of colon polyposis.
authors.affiliation: Department of Digestive Endoscopy, Division of South Building, Chinese PLA general hospital, Beijing 100853, China. ZiqiZhang45@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Shaobo
authors.initials: S
authors.lastname: Yang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000378:metabolism; D000328:Adult; D000368:Aged; D015153:Blotting, Western; D063646:Carcinogenesis / Q000378:metabolism; D003106:Colon / Q000378:metabolism / Q000473:pathology; D003111:Colonic Polyps / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D006801:Humans; D006965:Hyperplasia / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3